Automated Setup for Duty Cycle and Optical Power Correction in Lasers with External Electrical Modulation

Lasers with external electrical modulation are widely used in optical systems, but the generation of well-defined pulses often suffers from distortions in duty cycle and top optical power at high frequencies. This work addresses this limitation by presenting an automated setup for optical pulse correction that combines standard instrumentation with a feedback-based adjustment strategy. The system integrates a continuous-wave laser, a signal generator, an optical analyzer, and a control routine implemented in MATLAB (R2024b Campus Wide). Two nested loops are employed; the inner loop varies the amplitude of a sinusoidal modulation signal to regulate the duty cycle at the desired reference; the outer loop sends commands to the laser to adjust optical power level to a specified reference. Experimental validation shows that the proposed approach significantly improves pulse fidelity over a frequency range up to 100 MHz. In particular, the relative normalized root mean square error (NRMSE) was reduced by more than 97% compared with the case without adjustment, both for duty cycle (1–30 MHz) and top optical power (10–30 MHz). These results demonstrate that precise optical pulse control can be implemented with common laboratory instrumentation, providing a practical and accessible solution for automated pulse conditioning in externally modulated laser setups.